Climate change effects on organic carbon storage in agricultural soils of northeastern Spain

39 Pags., 5 Tabls., 4 Figs. The definitive version is available at: http://www.sciencedirect.com/science/journal/01678809The interactive effects of climatechange and atmospheric CO2 rise could have potential effects on both soilorganiccarbon (SOC) storage and the capability of certain management practices to sequester atmospheric carbon (C) in soils. In this study, we present the first regional estimation of SOC stock changes under climatechange in Spanish agroecosystems. The Century model was applied over a 80-yr period (i.e., from 2007 to 2087) to an agricultural area of 40,498 km2 located in northeast Spain under five different climate scenarios. The model predicted an increase in SOC storage in the 0–30 cm soil depth in all the climatechange scenarios tested (i.e., ECHAM4-A2, ECHAM4-B2, CGCM2-A2 and CGCM2-B2). Among climatechange scenarios, SOC stock changes ranged from 0.15 to 0.32 Tg C yr−1. The Century model also predicted differences in SOC sequestration among agricultural classes. At the end of the simulation period, the greatest SOC stocks were found in the rainfed arable land under monoculture and no-tillage (MC-NT) class and in the grape-olive (GO) class with average stocks greater than 80 Mg C ha−1. On the contrary, both the alfalfa (AF) and the cereal-fallow (CF) classes showed the lowest SOC stocks with predicted values lower than 60 Mg C ha−1. Under climatechange conditions, Spanish agriculturalsoils could act as potential atmospheric C sinks. Nevertheless, both the magnitude of the change in climate and the adoption of beneficial management practices could be critical in maximizing SOC sequestration.Jorge Álvaro-Fuentes was awarded with a Beatriu de Pinós Postdoctoral Fellowship by the Comissionat per a Universitats i Recerca del Departament d’Innovació, Universitats i Empresa, of the Generalitat de Catalunya and recently with a contract of the “Junta para la Ampliación de Estudios” (JAE-DOC) programme of the Consejo Superior de Investigaciones Cientificas (CSIC) co-financed by the European Social Fund. This work was partly supported by the Aragon Government and La Caixa (grant GA-LC-050/2011), the Comisión Interministerial de Ciencia y Tecnología of Spain (grants AGL2010-22050-C03-01/02) and the European Union (FEDER funds).Peer reviewe